Cavernicolous scorpions are fascinating with their choice of habitat and in some cases morphological adaptions. This group of scorpions are usually divided into four categories: Accidentals, trogloxenes, troglophiles, and troglobites. The categories are explained in the introduction of the article mentioned below. It is the two latter categories that have caves as their main habitats, but not all of the scorpions in these groups have troglomorphic traits (e.g. reduced eyes, reduced pigmentation etc.). They who do are true troglobites.
Javier Blasco-Aróstegui and Lorenzo Prendini have recently published a review of cavernicolous scorpions in the Balkans. They have classified the known cavernicolous species into the categories mention above, presented a redescription of the only real troglobitic species, Euscorpius studentium Karaman, 2020, and provided a identification key for the to the identification of cavernicolous scorpions occurring in the Dinaric Karst area.
Abstract:
Cavernicolous scorpions are difficult to collect and study due to their often inaccessible habitats. Some have evolved unique morphological adaptations, known as troglomorphies, including reduced sclerotization and pigmentation, reduction and/or loss of eyes, attenuation and elongation of the appendages, which assist them to thrive in dark, humid and low-energy input environments. Cavernicolous scorpions are classified into accidentals, trogloxenes, troglophiles, and troglobites. The Balkans, and particularly the Dinaric Karst region, host a diverse cave-adapted fauna, including scorpions. Despite an 1895 report of a blind scorpion from Bosnia and Herzegovina, the first truly troglobitic European scorpion, Euscorpius studentium Karaman, 2020, was only described a few years ago, based on two immature specimens. In the present contribution, this unique species is redescribed based on the first adult specimens; the ecological classification of all currently known cavernicolous Euscorpiidae Laurie, 1896, is updated; a key to the identification of cavernicolous scorpions occurring in the Dinaric Karst is provided; and the historical and geographical factors affecting the distribution and conservation of cavernicolous scorpions in the Balkans is reviewed.
Reference:
Blasco-Aróstegui J, Prendini L. Redescription of Euscorpius studentium Based on Adult Specimens; Updated Classification of Cavernicolous Euscorpiidae; and Review of Cavernicolous Scorpions in the Balkans. Diversity. 2024;16(12):737. [Open Access]
Thanks to Gerard Dupre and Siegfried Huber for informing me about this article!
